US Patent Laid-Open Publication No. 2008-0092877 relates to a method of collecting sunlight at a focus using a fresnel lens, reflecting the sunlight to a plane reflector, reflecting the sunlight downward to a central funnel type reflector, collecting the sunlight, and transmitting the sunlight to a transmitting pipe, but when plane reflected light is applied to a funnel type (cone type) downward reflector, light is radially reflected and thus parallel light is not formed and collected, whereby even if light is returned to the pipe, the light becomes diffused reflection light, and when light is transmitted to a remote place, much transmission loss occurs, and particularly, when light passes through a joint portion or a bending portion, much light loss occurs and thus the method has very bad transmitting efficiency and cannot transmit intended light.
Korean Patent Laid-Open Publication No. 1983-0009444,
Korean Patent Laid-Open Publication No. 1989-000905, and Korean Patent Laid-Open Publication No. 1988-058282 relates to a method of collecting light using a convex lens and transmitting the light to an optical fiber, and as chromatic aberration and diffused reflection occur, transmitting efficiency is very bad, and thus the method cannot transmit high density light to a remote place.
Korean Patent Laid-Open Publication No. 10-2003-0027529 relates to a method of forming a small module with a plurality of small dish type reflectors, a second reflector provided at a periphery of a focus of each reflector, each second reflector, and an optical fiber bundle formed with optical fibers disposed directly under the each second reflector and for applying collected sunlight and transmitting sunlight to a far separated absorber using the optical fibers and performing thermal conversion of the sunlight, and in this time, because light of wave lengths in a ultraviolet ray area and a far infrared ray area is absorbed to the optical fiber, thermal efficiency is not good, and while transmitting the sunlight, a loss by diffused reflection occurs in a bending portion of a transmission pipe and thus transmitting efficiency is not good.